There has been conventionally disclosed a permeable storage facility for rainwater and others in which a tabular member formed of flat plates and cylindrical portions opened in the flat plate is arranged below ground to form a rainwater storage space and each reinforcing material that extends in a horizontal direction is arranged between the flat plates of the tabular member which are adjacent to each other (see, e.g., Patent Reference 1). In this permeable storage facility, the cylindrical portions of the plurality of tabular members are stacked so as to abut on each other, and the vertical reinforcing materials are pierced in these cylindrical portions. Materials used for the reinforcing material extending in the horizontal direction and the reinforcing material extending in the vertical direction may be a metal such as stainless steel, concrete, or FRP (Fiber Reinforced Plastics) made of a resin and fibers. Further, shapes of the reinforcing material extending in the horizontal direction and the reinforcing material extending in the vertical direction may be a U-like shape, a prismatic shape, or an L-like shape.
To form the storage space of the thus configured permeable storage facility, first, the tabular member on a first level is arranged together with the reinforcing material extending in the horizontal direction, and the reinforcing material extending in the vertical direction is inserted into and erected in the cylindrical portion of the tabular member. Then, the tabular member on a second level is arranged in such a manner that its cylindrical portion abuts on the cylindrical portion of the tabular member on the first level, and the reinforcing material extending in the horizontal direction is fitted into a groove provided in the flat plate of the tabular member on the second level. Subsequently, the tabular member on a third level is laminated so as to be matched with the reinforcing material extending in the horizontal direction. Moreover, the tabular members and the reinforcing materials extending in the horizontal direction are sequentially overlapped, and an upper end of the reinforcing material extending in the vertical direction and the reinforcing material extending in the horizontal direction on the highest level are fixed.
In the thus configured permeable storage facility, the reinforcing material extending in the vertical direction is inserted so as to penetrate through the cylindrical portion forming the tabular member, and the reinforcing material extending in the horizontal direction is inserted between the flat plates forming the tabular member, thereby reinforcing the permeable storage facility.